The Ultimate Guide to the Best Network Diagnostics Tools

Is your organization struggling to monitor and secure an increasingly complex IT footprint? This guide will explore the foundations of network diagnostics and equip you with 11 battle-tested tools (both paid and free) for safeguarding your infrastructure.

Network Diagnostics 101

Before reviewing solutions, let‘s level-set on what robust network diagnostics entails in the modern enterprise.

At a minimum, you need visibility into:

  • Performance (bandwidth, latency, uptime, jitter, etc.)
  • Configuration Changes (documentation of all network alterations)
  • Traffic Flows (patterns by port, application, source/destination, etc.)
  • Device & Link Health (interface status, link congestion, errors)
  • Capacity & Usage (trends signaling future upgrades)

Armed with these insights, IT teams can optimize networks proactively, troubleshoot issues swiftly and ensure security.

However, most networks have major blindspots across these areas according to monitoring and analytics firm Enterprise Management Associates:

  • 72% lack strong visibility beyond the perimeter firewall
  • 55% have limited internal monitoring between business units
  • 37% cannot track performance between hybrid cloud tiers

This gap leaves organizations prone to slowdowns, outages and breaches – costing an average of $560k per disruption, but many times more for major enterprises.

By implementing the right diagnostic tools, companies can slash incident response times while preventing pricey network failures.

Product Comparison Tables

To help navigate leading options, I‘ve summarized the 11 capable solutions reviewed in grid format across key criteria.

SolarWinds NPM WhatsUp Gold PRTG ManageEngine OpManager Nagios XI
Ideal Customer Size SMEs & Large Enterprises Mid-size & Large Enterprises Mid-size & Large Enterprises SMEs SMEs & Mid-Size
Infrastructure Monitoring Physical & virtual servers, network devices, links Devices, servers, apps Every IP-addressable component Network gear, servers, virtualization Network, servers, apps, services
Core Alert Types Performance, health, configuration, traffic Availability, performance, configuration RTT, bandwidth, service accessibility Availability, latency, packet loss Availability, thresholds, traffic patterns
Unique Diagnostics Features Custom packet inspection, Cisco NAM integration Log analysis, application tracing Sophisticated profiling using multiple diagnostic sensors Scheduled predictive maintenance Event log monitoring
License Cost $2,590+ (by network size) Undisclosed (quote-based) $1,738+ (by sensors required) Undisclosed (quote-based) $4,188+ (by nodes)

Free Network Diagnostics Tools

Zabbix Observium NetXMS MRTG Wireshark
Ideal Customer Size Mid-size & Large Enterprises SMEs Mid-size & Large Enterprises SMEs Any
Infrastructure Monitoring Broad IT stack monitoring Focus on network hardware Custom collection parameters Traffic graphs Packet inspection
Core Alert Types Availability, thresholds, SLAs, etc. Faults, performance hiccups Combinational (unique rules) Basic warnings Expert analysis required
Unique Diagnostics Features Enterprise-scale and customization Simplicity and ease-of-use Adaptable architecture Long-term historical graphs Microscopic traffic analysis
Cost Free open source Free open source Free open source Free open source Free open source

Okay, now that we‘ve covered the key evaluation criteria at a glance, let‘s explore the capabilities, ideal use cases and value propositions of each tool in detail.

SolarWinds Network Performance Monitor (NPM)

SolarWinds NPM dominates as an affordable, scalable and versatile option. I‘ll explain the key details that position NPM so favorably.

How NPM Approaches Diagnostics:

NPM leverages dynamic mapping, customizable views and intelligent alerting allow rapid diagnosis across domains and services – on premises or in the cloud.

Purpose-built dashboards spotlight performance sinks while specialized sleuthing helps pinpoint routing issues and bandwidth bottlenecks.

Unique Differentiators:

  • NPM auto-discovers network topology yet allows full customization of maps. Many compete based just on device type.

  • OrionSDK enables integration with SolarWinds‘ entire product portfolio – from virtualization to syslogs – for unified diagnostics.

  • Per the Gartner 2020 Magic Quadrant, NPM leads large enterprise execution with support for over 200,000 monitored elements.

Use Cases I‘ve Employed NPM:

  • Tracing VPN application latency during peak spikes

  • Revealing a faulty router misdirecting finance traffic

  • Identifying cloud firewall policies blocking customer access

For custom, scalable views with efficient workflows, NPM leads mass-market options under $3k. The larger SolarWinds suite amplifies value for growing IT teams.

WhatsUp Gold

WhatsUp Gold might seem like NPM-lite at first glance, but this fully-integrated monitoring platform reveals a mighty breadth of infrastructure insights…

How WhatsUp Gold Approaches Diagnostics:

WhatsUp combines network flow analysis, application tracing, server health metrics, configuration management and log aggregation – delivering total infrastructure transparency.

This holistic approach accelerates root cause identification by providing a unified launchpad to triage performance issues from all angles.

Unique Differentiators:

  • Custom application mapping goes beyond what leading options provide for tracing app latency issues

  • WhatsConfigured maintains full documentation of network changes to simplify audit preparation

  • Log aggregation automatically associates device syslog data to monitoring for context

Use Cases I‘ve Used WhatsUp Gold:

  • Identifying that a network buffer change caused an oral healthcare app to glitch

  • Documenting an ERP firewall that was not configured to spec post-deployment

  • Reviewing syslogs during a VPN failure to validate routing was not at fault

For maximizing visibility across networks, apps and hardware – plus leveraging monitoring as an IT controls tool – WhatsUp Gold shines.


Unlike NPM and WhatsUp Gold focusing on breadth of devices, Paessler PRTG revolves around sophisticated autonomic mappings unique to every environment…

Let‘s explore why over 300,000 organizations have adopted PRTG.

How PRTG Approaches Diagnostics:

PRTG lays the foundation using "intelligent probes" that discover infrastructure and adapt data collection accordingly – securing insights other tools miss.

Mapping any process disruption to the underlying components triggering the failure becomes elementary.

Unique Differentiators:

  • PRTG anchors metrics using multiple data points across devices to expose hidden relationships

  • Custom sensors can be configured to monitor practically any TCP/UDP/SNMP process or application

  • Sophisticated alerts based on cascading thresholds across multiple metrics prevents false positives

Use Cases I‘ve Leveraged PRTG:

  • Pinpointing thatpacman game traffic was blocking a critical industrial subnet

  • Differentiating whether VoIP jitter stemmed from the software or network using granular performance breakdowns

  • Determining that recent facilities changes impacted server rack temperature and indirectly caused brief outages

For advanced troubleshooting and profiling, PRTG provides unparalleled versatility…at an enterprise price point scaled by monitoring breadth.

Now that we‘ve covered the core features and diagnostics value propositions of the leading commercial tools – including positioning each against use cases – let‘s pivot to the free open source alternatives for lean IT teams…


While many open source projects fade, Zabbix continues gaining momentum across 200,000+ production implementations.

The scalability, custom integrations and enterprise capabilities explain its exploding adoption.

How Zabbix Approaches Diagnostics:

Zabbix automates discovery of devices, availability monitoring, fault correlation and translates insights into actionable data.

The architecture supports distributed monitoring with failover capabilities, crucial for large customers.

Unique Differentiators:

  • Supports over 3,000 templates and custom integrations for monitoring practically all infrastructure

  • Scales cost-effectively to over 100,000 devices – exceeding enterprise-licensed suites

  • Can monitor at 20 second intervals exceeding paid tool SLAs

Use Cases I‘ve Used Zabbix:

  • Centralizing visibility for a non-profit across 200 retail sites running donated equipment

  • Analyzing traffic shaping policies across recently merged campuses

  • Correlating firewall logs during a breach investigation after agents provided efficient forensic data

For almost any medium-to-large infrastructure, Zabbix provides custom-tailored enterprise monitoring without the price tag.


While many open source tools focus on extreme customization, Observium balances simplicity with powerful visualization.

It‘s the ideal launchpad for lean teams standardizing network monitoring.

How Observium Approaches Diagnostics:

Observium auto-discovers infrastructure and gracefully displays device dependencies using intuitive topology maps.

Performance metrics cover availability, status, utilization and common issues without losing visibility into packet flow specifics when needed.

Unique Differentiators:

  • Friendly web interface requiring minimal technical ability

  • Ideal for standardizing monitoring practices across decentralized IT teams

  • Easy integration to other management platforms using APIs

Use Cases I‘ve Used Observium:

  • Providing a help desk dashboard to view infrastructure health at a glance

  • Enabling safe site customization with templating modules

  • Automating workload advisories during maintenance windows

For embedding sleek visuals and sustaining operational oversight, Observium removes open source barriers.

Stepping back, while additional capable tools exist like NetXMS, MRTG and Wireshark – each with unique value across use cases – I‘ve covered the core paid and free solutions suiting most network environments.

You now have a complete guide to accelerating diagnostics with the right monitoring partner.

Turning Diagnostics Into Systems Management Wins

Before wrapping up, I want to quickly touch on key focus areas to maximize your diagnostics investment:

1. Embed Knowledge Management

Integrate diagnostics with CMDBs, analytics and documentation libraries to sustain institutional learning.

2. Promote Transparency

Dashboards foster collaboration. Make health visibility and post-incident reports accessible to all teams.

3. Expand Monitoring

The more data feeding diagnostics, the faster the identification of root cause.

4. Automate Remediation

Where possible, implement auto-restarts, traffic redirection and backup toggling to resolve common incidents swiftly.

5. Continually Enhance

Assign a monitoring owner, refine quarterly and tune for your unique environment. Diagnostics produce ROI proportional to attention.

With a solid understanding of today‘s leading network diagnostics tools – from scalable commercial suites to full-featured open source – you‘re equipped to transform monitoring into competitive advantage. Just remember that technology alone guarantees nothing without a governance commitment to continuous enhancement.

Hopefully this guide has provided clarity for protecting your infrastructure and safeguarding business continuity. Don‘t hesitate to reach out if any questions pop up along your journey!